Brad Pitt: Happy Birthday Knox & Vivienne!

Brad Pitt takes another spin on his customized motorcycle in Hollywood on Saturday (July 11).

Tomorrow, the 45-year-old actor will celebrate the birthdays of his two youngest kids, twins Vivienne Marcheline and Knox Leon. They turn one-year-old tomorrow, July 12. Happy birthday, Knox and Vivienne!!!!

Earlier this week, writer and West Wing creator Aaron Sorkin was brought in to rewrite the script for the baseball drama Moneyball, which should help keep Brad attached as the movie’s lead.